Chris Kyle is considered an American hero. But heroism is a complex thing, for one man’s hero is another’s villain. In America he was mythologised by fellow troops as ‘The Legend’, in Iraq, he earned the moniker, ‘The Devil of Ramadi’. With American Sniper, an account based on Kyle’s book of the same name, director Clint Eastwood is only interested in one of those names.

Sniper documents Kyle’s entire life, from his early upbringing with a tough father who ruled by the belt and brought him hunting, through four tours in Iraq and the effects on his family life in between. Kyle clearly favours the war life over the domestic one but both present him with battles, both very real and life-threatening. Kyle, like many soldiers returning from conflict zones, suffers from PTSD that he is not inclined to acknowledge, particularly when it’s coming from the mouth of long-suffering wife Taya (Miller).

Kyle’s story is ripe for adaptation but Eastwood’s handling of is just as clumsy as it is uneasy to swallow, everything packaged in queasy American flag-waving. US troops are just good ol’ boys, the people of Iraq savages with names like The Butcher. He tries to show the stark contrast in how Kyle is at home with his wife and his real home, on tour, but each returning trip feels like a repeated scene, only his ageing kids suggest a time shift. The flow is constantly disturbed and some scenes — ones with Kyle’s father and speeches about wolves, sheep and sheep-dogs — are moan inducing while others — the final one, in particular — get interesting and never follow through. Whether an offset of his PTSD or his tough upbringing, Kyle was a really bad drunk in real life who regularly got in bar fights and is alleged to have killed two people trying to steal his truck. But there’s none of that here, its presence would only taint the aura of greatness in every proud frame.

It’s a shame, as arguably, Bradley Cooper has never been better, full committing emotionally and physically — beefing up to Kyle’s almost bloated muscular frame. He infuses Kyle with all the good there was about him: how he was deeply loyal, his support of ex-veterans with disabilities, and being a good but distant father. How his hat he wears while in a sniper’s nest remains a common fixture on his head back in America, and Cooper’s vacant glazes make Kyle seem morosely tragic. By comparison, his cast-mates get short shrift. Sienna Miller has the unfortunate role as the wife who has to react to loud bangs and muffled phone reception. When she shares scenes with Cooper and tries to help him cope, the script makes her belabour him and seem shrew. His fellow Navy Seals are faceless grunts who exist solely to be shot at some point and to die in Cooper’s arms.

Despite his Western background, Eastwood has mostly been against US conflict and pro-gun control which makes the unashamed jingoism all the more perplexing. But perhaps, it’s just another sign of a man in decline that’s included drab biopics, ill-advised Broadway adaptations and a movie about rugby; time, maybe for the gun-slinger to hang up his pistols.